Touching the sun: Tricor part of NASA project

By BOBBY WARRENStaff Writer

Wednesday

Aug 28, 2013 at 4:00 AM

WOOSTER -- A joke is told about how there is plan to send a manned mission to the sun. When concerns are raised about surviving such a trip due to the intense heat, the reply is, "Oh, don't worry, we're going at night."

Well, the workers at Tricor Metals on Old Lincoln Way West have become part of a NASA project that aims to send a spacecraft into the sun's corona, or outer atmosphere. The idea has been around in various concepts for about five decades, according to the project's website. If things go as planned, the launch of the Solar Probe Plus will come in 2018.

The project is part of NASA's goal to "touch the sun" through its Living with a Star program, and the space agency is working with Johns Hopkins University Applied Physics Laboratory, Laurel, Md., on the mission.

When it came time to have a prototype manufactured for one of the components, APL leaders reached out to Tricor, said Brandon Clark, who is the project manager on Tricor's end. "They could not find a good source, and they found us on the Internet. We checked out the drawings and had a lot of conversations about what they needed. We made a proposal and submitted it."

"This is so different for us," said Ron Krajcik, head of marketing for the Wooster manufacturer.

The Tricor structure is called the Truss Structure Assembly, Andy Driesman, Solar Probe Plus project manager, wrote in an email. It is used to support the spacecraft's Thermal Protection System and the Solar Array Cooling System.

"The TSA provides the 'standoff' distance between the very hot TPS and the spacecraft itself," Driesman wrote. "The TPS is a structure made from carbon-carbon face sheets which sandwich carbon foam. The top of the TPS is coated with a white optical layer that reflects much of the sun's energy. At closest approach, the TPS will see a little less than 3 million watts of energy from the sun -- and only (approximately) 20 watts enter the spacecraft.

"The TSA allows the bottom of the Thermal Protection System to have a view of deep space, to which it radiates much of this energy. The TSA also has support radiators that radiate heat from the solar arrays to deep space. The solar arrays on Solar Probe Plus are liquid-cooled; water is pumped through the solar arrays to radiators mounted on the TSA. And, the TSA provides mounting for five instrument components: The Solar Probe Cup, used to measure the solar wind plasma; and four electric field antennas, used to measure the electric field near the sun.

"The existing unit is scheduled for testing in October."

The assembly is made of a titanium alloy, and trying to come up with the prototype presented Tricor's team of engineers, fabricators and welders with some challenges.

During the welding process, the metal shrinks. The team, which included Pat Snyder and Kirk Zimmerman, had to make sure the structure would be the exact size after the welding process.

Another concern was the weight of the structure, Clark said. The assembly would need to withstand space travel and the heat, yet it had to be as light as possible. Trying to reduce the thickness of the tubing walls while maintaining the strength and integrity took some creative thinking.

The team eventually settled on a chemical milling process that removed material from the exterior of the tube instead of the interior.

"It was nice to be part of an important project like this," said Zimmerman, who handled welding duties. This project required the same specialized skills workers use on other projects, but it required tighter tolerances and holding the specifications APL wanted, he added.

Snyder had to make sure everything fit together. He enjoyed working on it, saying the Solar Probe Plus project was one of the better ones he has worked on.

"We are proud of our work force and their abilities to design and build the most advanced metal process equipment," Tricor President Mike Stitzlein said. "Most of our equipment is built to help our customers handle corrosives in chemicals, mining and allied markets. This project for Johns Hopkins' solar-bound spacecraft was a fine example of the kinds of challenging fabrications our people build."

Right now, the Solar Probe Plus is in what NASA calls the formulation phase, Driesman said. "The goal of this phase is threefold: 1) Develop a preliminary design for the mission, spacecraft, instruments and ground systems; 2) Bring all technology development items to level of maturity that eliminates the majority of the risk; and 3) Develop costs and schedules for the next phase that are consistent with NASA's budget and the launch date."

If everything goes well, the development phase would begin in mid-March, Driesman said, adding, "contingent on our successfully completing the three items above."

While Tricor helped with the prototype that will be used in testing, it is unknown whether the company will actually manufacture the assembly that goes into space, Driesman said. The project must successfully pass a review in mid-March to move on to the next phase.

Reporter Bobby Warren can be reached at 330-287-1639 or bwarren@the-daily-record.com. He is @BobbyWarrenTDR on Twitter.

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